Colorado Gov. John Hickenlooper shows off his socks--one with Democratic presidential candidate Bernie Sanders and the other with Republican candidate Donald Trump – before entering his former brewpub for a book signing event to mark the release of his autobiography Thursday, May 26, 2016, in Denver. Hickenlooper, who is term-limited, is doing book talk rounds this week, reviving speculation that he is positioning himself to join Hillary Clinton's presidential campaign ticket. (Photo by David Zalubowski/AP Photo)

A reveller takes part in the battle of “Enfarinats”, a flour fight in celebration of the Els Enfarinats festival on December 28, 2015 in Ibi, Spain. Citizens of Ibi annually celebrate the festival with a battle using flour, eggs and firecrackers. (Photo by Pablo Blazquez Dominguez/Getty Images)

A man dressed as Hindu Lord Shiva performs during a religious procession ahead of the Hindu festival of Maha Shivaratri, in Jammu February 23, 2017. (Photo by Mukesh Gupta/Reuters)

A reveller plays with tomato pulp during the annual Tomatina festival in Bunol, near Valencia, Spain on August 29, 2018. As every year on the last Wednesday of August, thousands of people visit the small village of Bunol to attend the Tomatina, a battle in which tons of ripe tomatoes are used as weapons. This year, a total of 145 tons of ripe tomatoes will be thrown between more than 22,000 participants. (Photo by Heino Kalis/Reuters)

British soldiers inspect a captured German place in the Horseguards' Parade, London during World War I in November 1914, with the London Eye in the background as a reminder of just how much has changed in the last 100 years. (Photo by Peter Macdiarmid/Getty Images)

A woman is tattooed during the Great British Tattoo Show in Alexandra Palace in north London, Britain May 23, 2015. (Photo by Neil Hall/Reuters)

A U.S. Marine leads training on a shooting range in France in an undated photo taken during the First World War. (Photo by Reuters/Courtesy Library of Congress)

Portuguese runner Adriele Silva gestures during the Great Wall Marathon at the Huangyaguan section of the Great Wall of China, in Jixian of Tianjin, China May 19, 2018. (Photo by Jason Lee/Reuters)